1. Field of the Invention
The present invention relates to a semiconductor device, a liquid discharge head having the semiconductor device, a liquid discharge cartridge, and a liquid discharge apparatus.
2. Description of the Related Art
A liquid discharge head which discharges a liquid from orifices is used as a printhead for an inkjet method. The inkjet method uses, for example, ink as a liquid, and controls ink discharge in accordance with a print signal to apply ink onto a printing medium such as paper. A liquid discharge apparatus having the liquid discharge head is applied as, for example, an inkjet printing apparatus. An inkjet printhead utilizing thermal energy selectively generates a bubble in a liquid by applying thermal energy generated by a heater to the liquid, and discharges an ink droplet from an orifice by the energy. Recently, the number of orifices is increasing to implement higher-speed printing. However, the resistance from the bonding pad to each heater varies greatly, making it difficult to uniformly supply power to a plurality of heaters. To solve this problem, Japanese Patent Laid-Open No. 2005-104142 discloses an arrangement in FIG. 5 in which a conductive line for supplying power to a heater is divided into a plurality of conductive lines to reduce variations of the resistances of the conductive lines. In FIG. 5, four heaters 101, four power transistors 102, and four level conversion circuits 103 form one segment. The line width is set larger for a VH line running to a segment at a position apart from the bonding pad, reducing variations of the resistances of VH lines running to respective segments. This also applies to GNDH lines running from the bonding pad to respective segments. This aims at uniformly supplying power to a plurality of heaters.